An update from the UK Health Security Agency included “Delta x Omicron Recombinant” as a signal that’s currently being monitored and investigated. The variant has been detected in the UK, it said.

Specific details about the variant have not yet been released and it’s unclear how many cases have been detected so far. The recombinant, which is also known as Deltacron, has so far not been designated as a variant of concern.

A recombinant happens when mutations from different strains come together in a new variant.

Concern about a Deltacron variant first emerged in January when a professor in Cyprus reported evidence of a Delta variant with Omicron-like features. The discovery was later dismissed as an error and the UK variant is unrelated to what happened in Cyprus.

The Omicron variant was first detected in November 2021 and rapidly spread around the world, displacing the Delta variant in just a matter of weeks in most countries. Omicron has since been shown to cause generally milder illness when compared to the Delta variant.